1. Field of the Invention
The present invention relates to a variable compression ratio apparatus. More particularly, the present invention relates to a variable compression ratio apparatus that varies the compression ratio of a mixed gas inside a combustion chamber according to driving conditions of an engine.
2. Description of Related Art
A variable compression ratio (VCR) apparatus varies the compression ratio of a mixed gas corresponding to operating conditions of an engine. According to the variable compression ratio apparatus, the compression ratio of the mixed gas is raised to decrease fuel consumption in a low load condition of the engine, and the compression ratio of the mixed gas is lowered to prevent “knocking” and to improve the output thereof in a high load condition of the engine.
The conventional variable compression ratio apparatus describes a multi-link type of control means that includes a connecting rod, which is connected to a piston to receive the explosion force of the mixed gas, and a pin link, which receives the explosion force from the connecting rod to rotate the crankshaft, to vary the rotation track of the pin link according to the driving condition of the engine such that the compression ratio of the mixed gas can be varied.
However, in the conventional variable compression ratio apparatus having a multi-link type of control means, a journal portion for mounting the control shaft is formed inside the crankcase of a cylinder block, and so on, so there is a drawback that the structure thereof is complicated.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.